Cancer: Causes and Types

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Questions and Answers

What is the primary cause of cancer in the human body?

An accumulation of beneficial variation in the genome over the course of a lifetime

An uncontrolled division of abnormal cells in a part of the body (correct)

Inheritance of a single mutated gene from a parent

A sudden mutation in a somatic cell

What type of cancer arises from connective tissue found in bones, tendons, cartilage, muscle, and fat?

Leukemia

Carcinoma

Sarcoma (correct)

Lymphoma

What is the effect of an activating mutation on a gene?

It causes the gene to be deleted from the genome

It causes reduced function of the gene

It causes the gene to be expressed at the wrong time, at the wrong level, or with a new function (correct)

It has no effect on the gene's function

What type of mutation is inherited from a parent and can increase the risk of certain cancers?

Germline mutation Signup and view all the answers

According to the Two Hit Hypothesis, what happens if one copy of a gene is mutated?

The other copy of the gene allows the protein to operate normally Signup and view all the answers

What is the increased risk for women who inherit a BRCA1/2 mutation?

Breast cancer Signup and view all the answers

What is the effect of an inactivating mutation on a gene?

It causes reduced function of the gene Signup and view all the answers

What is the primary location where leukemia arises?

Bone marrow Signup and view all the answers

What is required for a gene to be cancer-inducing?

Both copies of the gene must be affected Signup and view all the answers

What is the primary reason why normal human cells have a finite ability to undergo mitosis?

Due to the shortening of telomeres after each mitotic division Signup and view all the answers

What is the function of the tumor suppressor gene p53?

To stop the cell cycle upon detection of DNA damage Signup and view all the answers

Why do cancer cells avoid normal growth suppressor signals in the G1 checkpoint?

To continue proliferating Signup and view all the answers

What is the result of normal cells breaking down glucose through glycolysis?

The cell produces energy in the form of ATP Signup and view all the answers

What is the advantage of cancer cells diverting metabolites from glycolysis?

It allows the cell to divert metabolites for useful processes such as mitosis Signup and view all the answers

How do cancer cells maintain their ability to proliferate?

Due to the aforementioned Hallmarks 1-4 as well as over-active oncogenes Signup and view all the answers

What is the primary difference between normal cells and cancer cells in terms of telomeres?

Cancer cells are able to elongate their telomeres Signup and view all the answers

What is the primary function of the immune system?

To surveil the body and destroy foreign cells and pathogens Signup and view all the answers

What is the purpose of PDL-1 and PDL-2 antigens in cancer cells?

To inhibit T cells that would normally attack cancer cells Signup and view all the answers

What is the term for the process by which tumor cells move from the primary tumor to a different organ?

Metastasize Signup and view all the answers

What is the difference between benign and malignant tumors?

Benign tumors are unable to invade neighboring tissue or metastasize, while malignant tumors can Signup and view all the answers

What is the term for multiple metastatic tumors?

Metastases Signup and view all the answers

What is the result of primary tumor growth?

Cells grow uncontrollably until they become a mass, but some can remain benign Signup and view all the answers

What is a common site for secondary tumors?

Lung and liver Signup and view all the answers

What is a danger of metastasis?

All of the above Signup and view all the answers

What is the core idea behind the scientific theory of evolution?

All living organisms on Earth descended from a common ancestor Signup and view all the answers

What is adaptation in the context of evolution?

A trait that improves an organism's change for survival and reproduction Signup and view all the answers

What happens to organisms with traits that help them survive and reproduce?

They pass their characteristics to their offspring Signup and view all the answers

What is heritability in the context of evolution?

The passing of traits from parents to offspring Signup and view all the answers

What is the outcome of natural selection?

Helpful traits survive and spread through the population Signup and view all the answers

What is the estimated percentage of species that have ever lived on Earth that have become extinct?

99.9% Signup and view all the answers

What is the average lifespan of a species?

2-10 million years Signup and view all the answers

What is gradualism in the context of evolution?

The idea that species originate through a gradual change of adaptations Signup and view all the answers

What is the main idea behind the punctuated equilibrium hypothesis?

Speciation occurs rapidly, with long periods of genetic equilibrium in between Signup and view all the answers

What is the approximate timeframe for rapid speciation events according to punctuated equilibrium?

10,000 years or less Signup and view all the answers

What is genetic engineering?

The process of changing the DNA in living organisms to create something new Signup and view all the answers

What is the main goal of selective breeding?

To produce offspring with desired traits Signup and view all the answers

What is an example of hybridization?

Crossing a disease-resistant plant with one that has a large food-producing capacity Signup and view all the answers

What is the main risk of inbreeding?

Increased chance of genetic disorders Signup and view all the answers

What is cloning?

The process of creating an organism that is an exact genetic copy of another Signup and view all the answers

What is the relationship between genetic engineering and genetically modified organisms (GMOs)?

GMOs are a type of genetic engineering Signup and view all the answers

Study Notes

What is Cancer?

Cancer is caused by an uncontrolled division of abnormal cells in a part of the body
Caused by an accumulation of detrimental variations in the genome over a lifetime

Types of Cancer

Carcinoma: arises in epithelial tissue in internal and external linings of the body
Adenocarcinomas develop in organs or glands
Squamous cell carcinomas develop in squamous epithelium of organs, including skin, bladder, esophagus, and lung
Sarcoma: arises from connective tissue in bones, tendons, cartilage, muscle, and fat
Leukemia: cancers of the blood that originate in bone marrow
Lymphoma: cancers of the lymph system

Mutations

Activating mutations: cause genes to be expressed at the wrong time, level, or function
Inactivating mutations: reduce function of a gene (less RNA or protein is made)
Somatic mutations: acquired by somatic cells (all cells except eggs or sperm) and passed to daughter cells
Germline mutations (inherited mutations): present in germ cells (eggs or sperm) and inherited by offspring

Two Hit Hypothesis

Humans have two copies of every gene (diploid): one maternal, one paternal
Both copies of the gene must be affected for a gene to be cancer-inducing

Cellular Hallmarks of Cancer

Normal human cells have a finite ability to undergo mitosis due to telomere shortening
Cancer cells can exceed Hayflick's limit and continue to undergo mitosis
Cancer cells elongate telomeres using telomerase
Cancer cells avoid normal growth suppressor signals in the G1 checkpoint
Tumor suppressor genes, like p53, regulate cell death and proliferation
Cancer cells have altered metabolism, proliferating and diverting metabolites for useful processes
Cancer cells evade immune surveillance and can inhibit T cells with PDL-1/PDL-2 antigen

Metastasis

The process by which tumor cells move from the primary tumor to a different organ via lymph and/or blood
Benign tumors are masses of cells that cannot invade neighboring tissue or metastasize
Malignant tumors are capable of invading neighboring tissue and metastasizing
Dangers of metastasis include treatment for pain, and the need for ongoing treatment

Evolution

The scientific theory that all living organisms on Earth descended from a common ancestor
Principles of Darwinian Evolution: variation, heritability, overproduction, reproductive advantage, and adaptation
Natural Selection: organisms with traits that help them survive and reproduce pass their characteristics to their offspring
Variation exists among individuals within a population
Extinction is a natural and important part of evolution

Genetic Engineering

Changing the DNA in living organisms to create something new
Genetically Modified Organisms (GMOs) are the result of genetic engineering
Artificial selection: breeders choose which organisms to mate to produce offspring with desired traits
Hybridization: crossing two individuals with unlike characteristics to produce the best in both organisms
Inbreeding: breeding of organisms that are genetically similar to maintain desired traits

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Description

This quiz covers the causes and main types of cancer, including carcinoma, adenocarcinoma, and squamous cell carcinoma.